I prepare a menu plan. That saves time with shopping and saves me a headache and some stress every day. It also helps to control my budget.
For my planning I use a simple calendar. Usually I plan meals for one week. Sometimes, however, a whole month gets filled up as ideas pop up in my head or as I check my fridge or freezer for things to be used.
To make my planning easier I think in categories like: Soups or stews, wraps, pasta, casseroles, etc.